fix(cinder-understack): handle case when SVM name is already stripped

When we call the helper method to strip the SVM name from the volume
host name, it is possible it has already been stripped by another call
which is chaining into this call. So we need to handle that and load the
SVM name in a different way.

Author: skrobul

python/cinder-understack/cinder_understack/dynamic_netapp_driver.py

@@ -328,7 +328,23 @@ def _volume_to_library(self, volume) -> Generator[NetAppMinimalLibrary]:
         original_host = volume["host"]
         # svm plus pool_name
         svm_pool_name = volume_utils.extract_host(original_host, level="pool")
+        if not svm_pool_name:
+            raise exception.InvalidInput(
+                reason=f"pool name not found in {original_host}"
+            )
+
         svm_name = svm_pool_name.split(_SVM_NAME_DELIM)[0]
+        # workaround when the svm_name has already been stripped from the pool
+        prefix = self.configuration.netapp_vserver_prefix
+        if not svm_name.startswith(prefix):
+            LOG.debug(
+                "Volume host already had SVM name stripped %s, "
+                "using volume project_id %s",
+                original_host,
+                volume["project_id"],
+            )
+            svm_name = f"os-{volume['project_id']}"
+
         try:
             lib = self._libraries[svm_name]
         except KeyError: